PBA Construction Method Of Dongba Zhongjie Station Of Beijing Metro Line 3 Study On Construction Surface Settlement Control

The subway has sprung up like bamboo shoots after a rain,the number of underground buildings and pipelines is increasing,and the underground environment is complicated.There are heavy traffic on the surface,pedestrians in a hurry,standing buildings on the surface,and intricate underground pipelines,so PBA(hole pile method)has become the construction method of priority for construction workers.However,the PBA construction method still faces the problem of surface settlement caused by excavation.How to effectively control the surface settlement in the hole pile method and what scientific and reasonable method is used to predict the impact of PBA construction on the surface settlement will be The focus and difficulty of our research.This paper takes the PBA construction method of Beijing Metro Line 3 as a project reference,uses Excel and Midas GTS NX finite element analysis software to conduct research,and draws the rules.Provide a basis for the construction of the same construction method and the same land condition in the future.Start the research from the following points:1.Based on the project engineering data,combined with the construction content of the PBA construction method,use the MIDAS-GTS-NX numerical simulation software to establish a mechanical calculation model,simulate the full cycle of the station construction,and compare and analyze the actual monitoring data with the construction;2.Through the discussion and analysis of the measured data on the construction site and the results of the MIDAS-GTS-NX numerical simulation,the vertical displacement and settlement in the four typical construction stages of the excavation of the small pilot tunnel,the construction of the pile column system,the arching construction,and the excavation of the platform and hall floor are studied.Rules and analyze the reasons;3.According to the results of the MIDAS-GTS-NX numerical simulation software,the influence of the side pile parameters and the size of the small pilot tunnel on the ground settlement is analyzed;4.According to the analysis of field measurement data,the settlement during the excavation stage of the small pilot tunnel is the most obvious.For the analysis of the surface settlement data during the excavation of the small pilot tunnel,the Excel software is used to fit the settlement curve and select the appropriate fitting equation.Provide basis for future PBA construction in the same area and same location.